 function  getPath(){

     var pathName = document.location.pathname;
     var index = pathName.substr(1).indexOf("/");
    var result = pathName.substr(0,index+1);
    return result;
 }
 
function previewImage(file)  
{  
      
    fileName=$("#img").val();  
    $("#imgName").attr("value",fileName);  
      
  var MAXWIDTH  = 218;     //用来显示上传图片的宽度  
  var MAXHEIGHT = 158;     //用来显示上传图片的高度  
  var div = document.getElementById('preview');  
  if (file.files && file.files[0])  
  {  
    div.innerHTML = '<img id=imghead>';  
    var img = document.getElementById('imghead');  
    img.onload = function(){  
      var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);  
      img.width = rect.width;  
      img.height = rect.height;  
      img.style.marginLeft = rect.left+'px';  
      img.style.marginTop = rect.top+'px';  
    };  
    var reader = new FileReader();  
    reader.onload = function(evt){img.src = evt.target.result;};  
    reader.readAsDataURL(file.files[0]);  
  }  
  else  
  {  
    var sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';  
    file.select();  
    var src = document.selection.createRange().text;  
    div.innerHTML = '<img id=imghead>';  
    var img = document.getElementById('imghead');  
    img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = src;  
    var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);  
    status =('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height);  
    div.innerHTML = "<div id=divhead style='width:"+rect.width+"px;height:"+rect.height+"px;margin-top:"+rect.top+"px;margin-left:"+rect.left+"px;"+sFilter+src+"\"'></div>";  
  }  
}  
function clacImgZoomParam( maxWidth, maxHeight, width, height ){  
    var param = {top:0, left:0, width:width, height:height};  
    if( width>maxWidth || height>maxHeight )  
    {  
        rateWidth = width / maxWidth;  
        rateHeight = height / maxHeight;  
        if( rateWidth > rateHeight )  
        {  
            param.width =  maxWidth;  
            param.height = Math.round(height / rateWidth);  
        }else  
        {  
            param.width = Math.round(width / rateHeight);  
            param.height = maxHeight;  
        }  
    }  
    param.left = Math.round((maxWidth - param.width) / 2);  
    param.top = Math.round((maxHeight - param.height) / 2);  
    return param;  
}  